Filtering
Learn more about how to configure your SDK to filter events reported to Sentry.
When you add Sentry to your app, you get a lot of valuable information about errors and performance. And lots of information is good -- as long as it's the right information, at a reasonable volume.
The Sentry SDKs have several configuration options to help you filter out events.
We also offer Inbound Filters to filter events in sentry.io. We recommend filtering at the client level though, because it removes the overhead of sending events you don't actually want. Learn more about the fields available in an event.
Configure your SDK to filter error events by using the before_send callback method and configuring, enabling, or disabling integrations.
The before_send callback allows you to modify the event payload before the SDK sends the event to Sentry. You can also stop the event from being sent by returning None.
The callback receives two arguments: the event payload and a hint. The callback can return either the event payload to send to Sentry or None if the event should be dropped.
Any modifications to the event payload done in the callback, including adding data to the event and modifying or deleting existing event fields, will be reflected in Sentry.
Suppose that you wish prevent all errors of type ZeroDivisionError from being sent to Sentry and that you want to set an additional data attribute called "foo" to "bar" on all other events. You can achieve this behavior with the following before_send callback.
import sentry_sdk
from sentry_sdk.types import Event, Hint
def my_before_send(event: Event, hint: Hint) -> Event:
# Filter out all ZeroDivisionError events.
# Note that the exception type is available in the hint,
# but we should handle the case where the exception info
# is missing.
if hint.get("exc_info", [None])[0] == ZeroDivisionError:
return None
# We can set extra data on the event's "extra" field.
event["extra"]["foo"] = "bar"
# We have modified the event as desired, so return the event.
# The SDK will then send the returned event to Sentry.
return event
sentry_sdk.init(
# ...
before_send=my_before_send,
)
Note also that breadcrumbs can be filtered, as discussed in our Breadcrumbs documentation.
The before_send callback is passed both the event and a second argument, hint, that holds one or more hints.
Typically, a hint holds the original exception so that additional data can be extracted or grouping is affected. In this example, the fingerprint is forced to a common value if an exception of a certain type has been caught:
import sentry_sdk
def before_send(event, hint):
if 'exc_info' in hint:
exc_type, exc_value, tb = hint['exc_info']
if isinstance(exc_value, DatabaseUnavailable):
event['fingerprint'] = ['database-unavailable']
return event
sentry_sdk.init(
# ...
before_send=before_send,
)
For information about which hints are available see hints in Python.
When the SDK creates an event or breadcrumb for transmission, that transmission is typically created from some sort of source object. For instance, an error event is typically created from a log record or exception instance. For better customization, SDKs send these objects to certain callbacks (before_send, before_breadcrumb or the event processor system in the SDK).
Hints are available in two places:
before_send/before_breadcrumbeventProcessors
Event and breadcrumb hints are objects containing various information used to put together an event or a breadcrumb. Typically hints hold the original exception so that additional data can be extracted or grouping can be affected.
For events, hints contain properties such as event_id, originalException, syntheticException (used internally to generate cleaner stack trace), and any other arbitrary data that you attach.
For breadcrumbs, the use of hints is implementation dependent. For XHR requests, the hint contains the xhr object itself; for user interactions the hint contains the DOM element and event name and so forth.
import sentry_sdk
def before_send(event, hint):
if 'exc_info' in hint:
exc_type, exc_value, tb = hint['exc_info']
if isinstance(exc_value, DatabaseUnavailable):
event['fingerprint'] = ['database-unavailable']
return event
sentry_sdk.init(
# ...
before_send=before_send,
)
originalException
The original exception that caused the Sentry SDK to create the event. This is useful for changing how the Sentry SDK groups events or to extract additional information.
syntheticException
When a string or a non-error object is raised, Sentry creates a synthetic exception so you can get a basic stack trace. This exception is stored here for further data extraction.
event
For breadcrumbs created from browser events, the Sentry SDK often supplies the event to the breadcrumb as a hint. This can be used to extract data from the target DOM element into a breadcrumb, for example.
level / input
For breadcrumbs created from console log interceptions. This holds the original console log level and the original input data to the log function.
response / input
For breadcrumbs created from HTTP requests. This holds the response object (from the fetch API) and the input parameters to the fetch function.
request / response / event
For breadcrumbs created from HTTP requests. This holds the request and response object (from the node HTTP API) as well as the node event (response or error).
xhr
For breadcrumbs created from HTTP requests made using the legacy XMLHttpRequest API. This holds the original xhr object.
By default the Python SDK captures all error logs as events. If you see a particular kind of error very often that has a logger tag, you can ignore that particular logger entirely. For more information see our logging integration.
To prevent certain transactions from being reported to Sentry, use the traces_sampler or before_send_transaction configuration option, which allows you to provide a function to evaluate the current transaction and drop it if it's not one you want.
Note: The traces_sampler and traces_sample_rate config options are mutually exclusive. If you define a traces_sampler to filter out certain transactions, you must also handle the case of non-filtered transactions by returning the rate at which you'd like them sampled.
In its simplest form, used just for filtering the transaction, it looks like this:
def traces_sampler(sampling_context):
if "...":
# Drop this transaction, by setting its sample rate to 0%
return 0
else:
# Default sample rate for all others (replaces traces_sample_rate)
return 0.1
sentry_sdk.init(
# ...
traces_sampler=traces_sampler,
)
It also allows you to sample different transactions at different rates.
If the transaction currently being processed has a parent transaction (from an upstream service calling this service), the parent (upstream) sampling decision will always be included in the sampling context data, so that your traces_sampler can choose whether and when to inherit that decision. In most cases, inheritance is the right choice, to avoid breaking distributed traces. A broken trace will not include all your services. See Inheriting the parent sampling decision to learn more.
Learn more about configuring the sample rate.
In Python, a function can be used to modify the transaction event or return a new instance. If you return None, the event will be discarded.
import sentry_sdk
def strip_sensitive_data(event, hint):
# modify event here
return event
sentry_sdk.init(
# ...
before_send_transaction=strip_sensitive_data,
)
Addtionally, you may filter out transaction events based on the request URL, like /healthcheck.
from urllib.parse import urlparse
def filter_transactions(event, hint):
url_string = event["request"]["url"]
parsed_url = urlparse(url_string)
if parsed_url.path == "/healthcheck":
return None
return event
sentry_sdk.init(
# ...
before_send_transaction=filter_transactions,
)
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").